Method and device for the sprinkling of a cultivated field

ABSTRACT

A method of sprinkling water over a large cultivated area and a device for performing this method, where a sprinkler head on a sprinkler carrier is advanced along a straight-line distance by pulling a long, flexible water supply hose along this line, the hose being slowly wound onto a horizontal drum, while feeding water to the sprinkler. In order to avoid deviations of the advancing hose from the straight-line to be travelled by the sprinkler, the hose drum is slowly displaced along its axis by synchronously shifting a carriage on which it is mounted, so that the point at which the straight portion of the water hose extends from the drum remains in alignment with the line to be travelled by the sprinkler. The method further includes steps for repeating the sprinkling procedure on adjacent lines of sprinkler travel, and the device suggested for this includes a wheeled vehicle frame which is movably positioned on a transverse access lane to the field. The device further includes automatic controls for starting and stopping the sprinkling operation.

White States Patent 1 1 Perrot et a1.

[ June 19, 1973 METHOD AND DEVICE FOR THE Primary Examiner-Richard A. Schacher SPRINKLING OF A CULTIVATED FIELD Attorney-Arthur Schwartz, Eugene Mar, Joseph [76] Inventors: Alexander Perrot, Hindenbrugstr. 6; Geger et Emil Schucker, Lange Steige 51, both of 7260 Calw, Germany 1 ABSTRACT A method of s rinklin water over a lar e cultivated [22] Flled' 1971 area and a devi e for pirforming this method, where a [21] Appl. No.: 188,300 sprinkler head on a sprinkler carrier is advanced along a straight-line distance by pulling a long, flexible water su l hose alon this line, the hose bein slowl [30] Forelgn Apphcatlon Pnonty Data wdiFnZl onto a hori zontal drum, while feeding iater tr 1971 Germany P 20 53 77M the sprinkler. In order to avoid deviations of the advancing hose from the straight-line to be travelled by [52] US. Cl. 239/1, 239/189, 239/197, the Sprinkler the hose d i l wly displaced along 242/86'2 242/86'8 242/158 R its axis by synchronously shifting a carriage on which [51] Int. Cl B65h 75/40 it is mounted so that the point at which the Straight [58] Fleld of Search 239/172, 183, 195, portion of the water hose extends from the drum 239/197 189; 242/158 mains in alignment with the line to be travelled by the sprinkler. The method further includes steps for repeating the sprinkling procedure on adjacent lines of sprin' [56] References cued kler travel, and the device suggested for this includes UNITED STATES PATENTS a wheeled vehicle frame which is movably positioned 3,445,066 5/1969 Mohar 239/199 X on a transverse access lane to the field. The device fur- 3,456,899 7/1969 Smith et a1..... 242/158 R ther includes automatic controls for starting and stop- Armstrong X the sprinkling peration 3,614,019 10/1971 Slator et a1 242/158 R 3,628,728 12 1971 Polutnik et a1. 239 199 x 13 Claims, 6 Drawing Figures 4 2 M M h 12 i i 9| 6 12 5" a 8 I 4371a 1 5 I J l PATENIH} JUN I 9. I973 Fig.3

SHiU 2 OF 2 INVENTOR! Alexander Pm'raf' BY Emil Jrhucl'tr BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to sprinkling systems, and in particular to a method and a device for the sprinkling of a cultivated field by means of a moving sprinkler and sprinkler carrier whose water supply hose is wound onto a hose drum, the sprinkler carrier being advanced by the winding action of the hose.

2. Description of the Prior Art From the prior art is known a sprinkler system where the sprinkler carrier is advanced by the winding action of the hose drum, but it has the shortcoming that the progressive addition of hose coils onto the drum causes the winding point of the hose, and thus the direction of pull on the sprinkler carrier, to shift sideways. This makes it necessary to repeatedly interrupt the sprinkling action in order to correct the position of the drum relative to the motion of the sprinkler carrier. The sprinkling action obtained in this manner is somewhat irregular and it requires repeated interference by an operator.

SUMMARY OF THE INVENTION The invention has as its major objective the provision of a method and device which permits the attendancefree continuous sprinkling of a large cultivated field, whereby the area to be sprinkled receives a very evenly distributed amount of water and no damage occurs to any of the sprinkled cultivated plants. Furthermore, the attendance required by the device is to be minimal.

In order to attain the above mentioned objectives, the invention suggests a sprinkling method in which the hose drum undergoes an axial translating motion while the hose is wound or unwound from the hose drum, so

as to maintain the winding point at the same axial position during the entire winding or unwinding operation. This assures that the sprinkler carrier, which is advanced by the hose being wound onto the hose drum, moves along a precise straight line as it is being pulled by the hose.

In a preferred method of the invention, the hose is wound onto the hose drum in a single layer.

If a cultivated field larger than that covered by a single sprinkler path is to be treated, the hose drum, which is mounted on a vehicle frame, is advanced sideways by a distance corresponding approximately to the width covered by the sprinkler head. The sprinkler carrier with the attached outer hose end is then again pulled across the field, while the hose drum shifts across the vehicle accordingly. After the sprinkler carrier has been moved to its most distant point, the sprinkling action can be started from the hose drum vehicle and need not be interrupted until the sprinkler carrier has covered the entire distance between its farthest point and the hose drum. i The device suggested by the invention for the performance of this method includes a vehicle frame on which the hose drum is supported by means of a longitudinal carriage which can be advanced along the longitudinal axis of the vehicle in synchronism with the winding or unwinding of the hose on the hose drum. The drive for the winding of the hose onto the drum and for the simultaneous axial advance of the carriage on the vehicle is likewise arranged on the vehicle.

The method and device as suggested have the additional advantage that the hose need not be guided as it is wound onto the drum or unwound from it, thereby eliminating any friction and consequent possible damage to the hose. l

The sprinkler head itself is preferably a swivelling sector sprinkler which is mounted on a sprinkler carrier. However, sprinkling may also be performed by a fixed sprinkler jet which covers an approximately rectangular area.

BRIEF DESCRIPTION OF THE DRAWINGS Further special features and advantages of the inven tion will become apparent from the description following below, when taken together with the accompanying drawings, which illustrate, by Way of an example, an embodiment of the method and device of the invention, represented in the various figures as follows:

FIGS. la, lb and 10 show, in a schematic representation, the steps performed during the method of the invention;

FIG. 2 shows, in an elevational sideview, a vehicle frame and a hose drum with its carriage mounted thereon in an embodiment of the invention;

FIG. 3 shows a sideview of the device of FIG. 2; and

FIG. 4 shows a plan view of the device of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As can be seen from FIGS. la, lb and 1c, the cultivated area which is to be sprinkled with water is bordered on one side by an access lane 13. On this lane is stationed a vehicle which can be moved between the different positions shown in the drawing by means of a tractor 18, for example. The FIGURE portions la, lb and 1c represent portions of consecutive steps performed during the method as suggested by the invention. During each operational cycle, the device sprinkles the area A (as delineated by a broken line in FIG. 10). The vehicle 3 remains stationary during the sprinkling cycle. Between sprinkling cycles, the vehicle 3 has to be advanced along the access lane 13 by a distance which corresponds approximately to the width covered by the sprinkler.

Prior to startup of the sprinkling operation, the sprinkler carrier 1 (which, as such, is of a known design) and the attached water hose 2 must be unwound from the hose drum 4 by pulling the sprinkler carrier across the cultivated field along a straight line, using the tractor 18, for example. While the hose 2 is unwound from the drum 4, the latter is synchronously displaced along the longitudinal axis of the vehicle 3, so as to maintain the unwinding position of the hose 2 at a fixed point, thereby avoiding any lateral shifting of the hose. To accomplish this, the hose drum 3 must advance by an amount corresponding to the diameter of the hose, for each drum rotation. Thus, the unwinding point of the hose 2 from the drum 4 remains stationary with respect to the vehicle 3 and with respect to the field. The hose 2 is wound onto the drum 4 in a single layer, so that the drum is empty, when it has reached its rear end position (see FIG. lb). The sprinkler head and sprinkler carrier, symbolized by the numeral 1, are now in their starting positions, as shown in FIG. 1b. The automatic sprinkling operation can now be started either through a remote control device on the vehicle 3, or by means of a predetermined program, using a timing device, for example. The controls are so arranged that, simultaneously with the start of sprinkling, the drum 4 is actuated by a drive mechanism which slowly rotates the drum at a constant speed, thereby winding the extended hose 2 onto the drum periphery and slowly advancing the sprinkler carrier 1 toward the vehicle 3. While the hose is being pulled in and wound onto the drum 4, the drum itself also undergoes a longitudinal displacement to accommodate the hose coils on the drum periphery without shifting the winding point relative to the vehicle. Thus, the sprinkler carrier can be pulled all of the way from its extended position to a position near the vehicle, whereby the sprinkler head follows a precise straight-line motion while sprinkling the area A. During this time, the hose drum 4 has shifted from its extreme rear (left) position to its extreme forward (right) position on the carrier vehicle. The drum drive is automatically disconnected from the drum axis, when the hose 2 is again unwound for a new sprinkling cycle (see FIG. 1a).

A preferred embodiment provides that the hose drum 4 rotates at a speed of 1.6 revolutions per hour, which corresponds to a linear advance of the sprinkler carrier and sprinkler head of meters per hour. The motor used for driving the drum 4 may be an electric motor or a self-contained internal combustion engine. As such drive motors commonly operate at rather high speeds, up to 14,000 r.p.m. for example, the device requires a transmission with a corresponding transmission ratio to obtain the necessary slow speed on the drum axis.

This device assures that, during the entire sprinkling cycle, the sprinkler carrier is always pulled at a right angle to the drum axis, so that, in the case where it is positioned between two rows of plants, it can move between those rows without causing any damage to the plants. The sprinkling thereby obtained is very even, by virtue of the fact that the drum is being driven at a constant speed and that the winding diameter remains the same during the entire cycle. Thus, the sprinkler not only moves along a precise straight line, but it also moves with a constant rate of advance. When the sprinkler carrier has reached the position shown in FIG. 10, the drum drive is automatically stopped and the water supply is simultaneously shut down.

A very important advantage afforded by the present invention is the fact that no attendance is required for the device during the entire sprinkling cycle. Even between cycles, there is no need for such skilled work as the layout of pipes, the installation of sprinkler posts, and the opening and closing of hose couplings.

In FIGS. 2 through 4 are given more detailed illustra tions of the design and operation of the device of the invention.

On a vehicle frame 3 is mounted a longitudinal carriage 6 which includes two vertical supports 6 with two axially aligned journals 6" for the drum shaft 8. The carriage 6 is guided for longitudinal displacement along the axis of the vehicle frame 7. In the FIGS. 2 through 4, the hose drum 4 is shown in its extreme forward position on the vehicle, the extreme rearward position being indicated in FIG. 2 by a dotted line. The translation drive for the carriage 6 is synchronously coupled to the rotary drive for the drum 4. Their common power source is a drive unit 11 (drive motor and gear transmission) which is mounted on the carriage 6. The

output shaft of the gear transmission has a considerably lower speed than the motor itself, and its speed is further reduced through a drive transmission 9 which is arranged between the output shaft and the drum shaft 8. This may include an intermediate gear shaft 9" as well as a chain drive with chain wheels 9' and 9". The intermediate gear shaft 9" is preferably arranged near the center plane of the vehicle. The drive for the axial displacement of the carriage 6 is derived from the drum shaft 8 by means of a chain transmission which includes the chain wheels 12 and 12'. The lower chain wheel 12' drives, via a bevel gear, a transverse shaft 12" which extends between the two carriage guide profiles 3' and includes a drive'pinion 12" on each of its extremities. The drive pinions 12" each engage a row of holes in the guide profiles 3', cooperating with these holes in the manner of a rack and pinion. The two drive pinions 12" thus remain always in positive driving engagement with the drum shaft 8 so that, whenever the drum is rotated, it also makes a corresponding longitudinal displacement on the vehicle frame. The drive ratio between the drum shaft 8 and the drive pinions 12" is such that, for each full rotation of the drum, the carriage 6 is moved by a distance equivalent to the diameter of the hose 2 being wound or unwound on the drum.

The dimensions chosen for the total length of the hose 2 and for the length of the hose drum 4 are preferably such that the hose 2 can be wound onto the drum in a single layer.

The sprinkler used in connection with this preferred embodiment of the invention is a swivelling sector sprinkler which covers a semi-circular area as indicated in FIG. lb. However, it is equally possible to use a fixed sprinkler head on the sprinkler carrier whose jet covers both sides in a generally rectangular pattern. In both cases, it is important that at the termination of the sprinkling cycle, as indicated in FIG. 10, the sprinkling operation stops before it covers the vehicle 3 and the access lane 13. The sprinkler carrier may be in the form of a sled which slides on the ground.

The drive unit 11, the transmission drive 9 and the axial displacement drive 12 for the carriage are ar ranged on the carriage itself, on the forward side of the vehicle. When the hose 2 is completely unwound from the drum 4, the latter is in its extreme rearward position, as indicated in FIG. 1b. Correspondingly, when the hose 2 is fully wound onto the drum, with the full weight of the hose on the carriage 6, the latter is in its normal forward position on the vehicle, without any overhang over the wheels of the vehicle frame. Only the empty drum, in its extreme rearward position, as outlined in FIG. 2, is in part overhanging the rear axis of the vehicle frame, while the winding point of the hose is still located between the supporting points of the vehicle frame. The water for sprinkling may be supplied by a water hydrant which, via a connecting hose (not shown), is connected to a rotary pipe coupling 14 which has an intake connection 14'. From the rotary pipe coupling 14 the water flows through the forward portion of the drum shaft 8 and into the radially extending inward end of the water hose 2. As can be seen in the FIGS. 2 and 4, the point 16, where the hose 2 is wound or unwound from the drum, is at the lowest point of the drum, thus giving the vehicle adequate stability during the winding and unwinding operations. At the end of the sprinkling cycle the water flow is automatically shut off by a valve which is operated either mechanically by the moving hose itself, or electrically by a switch which is actuated by a certain portion of the hose being wound onto the drum, or alternately by a position switch on the carriage 6 which indicates arrival of the sprinkler carrier at its end position, shown in FIG. llc.

During the unwinding operation (FIG. lla), prior to starting of a new sprinkling cycle, it is necessary that the drum shaft 8 be disconnected from the drive unit ill to allow the drum to rotate freely when the sprinkler carrier l and the hose 2 are pulled into the field. For this purpose, the device includes a clutch mechanism which is arranged between the drum shaft 8 and the upper chain wheel 9" and which is operated automatically in response to the presence or absence of water pressure inside the hose 2. This automatic clutch mechanism includes a hydraulic cylinder 17 which extends coaxially with the drum shaft 8 and is firmly attached thereto. This hydraulic cylinder 117 includes a spring loaded piston and piston rod which moves toward the chain wheel 9", when the piston is pressurized with water, as the sprinkling operation starts. The chain wheel 9" which, during the unwinding operation is free to rotate relative to the drum shaft 8, is engaged by the piston rod of the hydraulic cylinder 17, thereby coupling the chain wheel 9" to the drum shaft 8. Simultaneously with the start-up of the sprinkling operation and the actuation of the coupling mechanism 17 is also started the drive unit 11, which thus causes the drum to start its slow rotation by which the sprinkler carrier is advanced toward the supply vehicle.

Similarly, when the supply of sprinkling water is automatically shut down at the end of the sprinkling cycle, the piston rod of the coupling cylinder 17 is retracted by the action of its spring, so that the drum shaft is uncoupled from the driving chain wheel 9", thereby automatically freeing the drum for the subsequent unwinding operation.

it should be obvious that the size of the area A which is sprinkled during one cycle can be varied within a wide range by chosing different dimensions for the hose drum 4 and the vehicle frame 3. in the example chosen for illustration, the length of the area A is approximately 300 meters, and its width is approximately 60 meters, so that the vehicle has to be translated over a distance of somewhat less than 60 meters between cycles (to assure a small overlap between adjacent sprinkling areas). The hose drum itself has a length of approximately 3 meters.

It is also possible to modify the device of the present invention so that the hose 2 is wound onto the drum 4 in at least two superposed layers. With two such layers, for example,,the resultant change in the speed of advance of the sprinkler head remains still negligible. On the other hand, however, the superposed position of two layers on the drum will entail a far greater strain on the hose itself. if is further necessary, in such a case, to provide an automatic reversing mechanism on the axial displacement drive which would come into operation as soon as the winding or unwinding operation passes through the transition from one layer of hose coils to the next layer.

During the operations of winding and unwinding of the hose 2 on the drum 4, the latter is pulled sideways 6 weight-carrying rollers 15, but also with lateral thrust rollers (not visible in the drawing), which support the carriage 6 horizontally against vertical guide portions in the longitudinal guide profiles 3' of the frame 3.

While the invention has been described, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses or adaptations of the invention following in general the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

We claim:

1. A method of sprinkling water over a cultivated field comprising the steps of:

positioning a movable sprinkler at the far end point of a straight-line distance to be travelled by the sprinkler;

slowly advancing the sprinkler along the line to be travelled, using a flexible, pull-resistant water sup ply hose which is longer than the distance and which extends along this line, the far end of the hose being connected to the sprinkler;

continually winding onto a hose drum positioned this side of the near end point of the distance, the water supply hose as it is being pulled along the line;

slowly displacing the hose drum in a transverse movement relative to said straight line as it rotates to wind up the water supply hose, so that the point at which the hose is wound onto the drum remains always in alignment with the line to be travelled by the sprinkler;

pumping water from a water supply into the drumside end of the water supply hose as it is being wound onto the drum while advancing the sprinkler toward the drum; and

stopping the winding, drum-displacing and pumping actions when the sprinkler has reached the near end point of its travel distance;

translating the sprinkler including the drum with the wound-up hose and the drum support structure into alignment with another straight-line travel distance;

pulling the movable sprinkler with the attached far end of the water supply hose over the new travel distance, in a direction perpendicular to the drum axis, until it reaches the far end point of the new travel distance, thereby unwinding the hose from the hose drum; and

repeating the steps of advancing, winding, displacing and pumping as previously set forth.

2. A device for the sprinkling of a predetermined area, such as cultivated field with water from a pressurized water supply, comprising in combination:

a movable sprinkler carrier with a sprinkler head mounted thereon;

a long, flexible water supply hose connected on one end thereof to the sprinkler head and capable of advancing the sprinkler carrier in the direction of the hose, when the latter is being pulled;

a hose drum to which the other end of the water supply hose is permanently attached and which is capable of winding up substantially the entire length of the flexible supply hose in the form of a hose coil, the drum including a horizontal central shaft and two journals for the support of the shaft;

a drum carriage in the form of a frame supporting the drum shaft by its two journals;

a stationary drum carriage support, the support including a drum carriage guide permitting movement of the drum carriage in the sense of an axial displacement of the drum;

means for continuously driving the drum so as to slowly wind up the water supply hose, thereby steadily advancing the sprinkler carrier in the direction in which the hose is being pulled; the drum driving means being mounted on the drum carriage and including a drive motor, a speed-reducing transmission between the drive motor and the drum shaft, and means for disconnecting the drum shaft from the transmission;

means for simultaneously displacing the drum carriage and the drum in an axial direction at a rate which corresponds to the rate of axial increase or decrease of the hose coil on the drum as the hose is wound onto the drum or unwound from it, respectively, so that the axial point at which the straight portion of the hose extends from the drum remains the same with respect to the ground on which the device is stationed; and

means for connecting the water supply to the attached end of the water supply hose in the hose drum, to allow pressurized water to flow through the rotating hose coil on the drum and through the straight portion of the water supply hose into the sprinkler head, as the latter is advanced toward the hose drum; said connecting means including a central duct inside the drum shaft, a connection between this duct and the attached end of the water supply hose, a rotary pipe coupling at one end of the drum shaft, and a water supply line linking the device to the pressurized water supply, the rotary pipe coupling including a non-rotating outer coupling portion to which one end of the water supply line is connected.

3. A sprinkling device as defined in claim 2, wherein:

the speed-reducing transmission includes a toothed wheel on the drum shaft, and the disconnecting means include a water-pressure-operated mechanical coupling between the toothed wheel and the drum shaft.

4. A sprinkling device as defined in claim 3, wherein:

the mechanical coupling between the toothed wheel and the drum shaft includes a hydraulic cylinder mounted on the drum shaft in parallel alignment thereto, and a spring-loaded piston with a piston rod extending from the cylinder toward the toothed wheel, the toothed wheel having a row of holes which can be engaged by the fully extended piston rod, when the piston is moved against its spring under the influence of the water pressure coming from the water supply, the spring causing the piston rod to release the toothed gear as soon as the water supply is shut off.

5. A sprinkling device as defined in claim 2, wherein:

the drum carriage guide on the carriage support includes two horizontally spaced, parallel guide profiles, and the drum carriage includes a plurality of 6 oppositely arranged guide rollers engaging the two guide profiles. 6. A sprinkling device as defined in claim 5, wherein:

the drum displacing means include linear drive means on the drum carriage which engage the carriage support, and a fixed-ratio drive transmission between the drum shaft and the linear drive means.

7. A sprinkling device as defined in claim 6, wherein:

each of the two guide profiles includes a row of vertically oriented regularly spaced holes, and the linear drive means of the drum carriage include a transverse shaft joumalled on the drum carriage and a sprocket on each shaft end engaging one of the two rows of guide profile holes in the manner of a rackand-pinion drive; the fixed'ratio drive transmission including an intermediate shaft in parallel align ment with the drum shaft, a chain drive linking these two shafts, and a bevel gear connecting the intermediate shaft with the transverse shaft of the linear drive means.

8. A sprinkling device as defined in claim 2, wherein:

the hose drum has a cylindrical winding periphery and such an axial length that is can accommodate the entire coilable length of the water supply hose in a single-layer coil.

9. A sprinkling device as claimed in claim 8, wherein:

the stationary drum carriage support is a vehicle frame with two axles and four wheels thereon, representing a rectangular ground support area, the drum carriage and the drum carriage displacement means being so arranged that the empty hose drum at least partially overhangs the rear axle, While the drum driving means and drum displacement means, as well as the point at which the hose extends from the drum, remain located above the ground support area, whereas the full hose drum occupies a forward position in which its weight is distributed approximately evenly between the two vehicle frame axles.

10. A sprinkling device as defined in claim 2,

wherein:

11. A sprinkling device as defined in claim 2,

wherein:

the water supply line includes means for shutting off the water supply; and

the device further includes means for closing these shut-off means and for stopping the drum motion in response to the completion of the hose-winding operation when the sprinkler carrier has reached its nearest position to the hose drum.

12. A sprinkling device as defined in claim 2,

wherein:

- the sprinkler head is a swivelling sector sprinkler covering a semicircular area extending away from the hose drum. 13. A sprinkling device as defined in claim 2,

wherein:

the sprinkler head is a fixedly mounted sprinkler jet covering an approximately rectangular area extending to either side of the sprinkler carrier and away from the hose drum. 

1. A method of sprinkling water over a cultivated field comprising the steps of: positioning a movable sprinkler at the far end point oF a straight-line distance to be travelled by the sprinkler; slowly advancing the sprinkler along the line to be travelled, using a flexible, pull-resistant water supply hose which is longer than the distance and which extends along this line, the far end of the hose being connected to the sprinkler; continually winding onto a hose drum positioned this side of the near end point of the distance, the water supply hose as it is being pulled along the line; slowly displacing the hose drum in a transverse movement relative to said straight line as it rotates to wind up the water supply hose, so that the point at which the hose is wound onto the drum remains always in alignment with the line to be travelled by the sprinkler; pumping water from a water supply into the drum-side end of the water supply hose as it is being wound onto the drum while advancing the sprinkler toward the drum; and stopping the winding, drum-displacing and pumping actions when the sprinkler has reached the near end point of its travel distance; translating the sprinkler including the drum with the wound-up hose and the drum support structure into alignment with another straight-line travel distance; pulling the movable sprinkler with the attached far end of the water supply hose over the new travel distance, in a direction perpendicular to the drum axis, until it reaches the far end point of the new travel distance, thereby unwinding the hose from the hose drum; and repeating the steps of advancing, winding, displacing and pumping as previously set forth.
 2. A device for the sprinkling of a predetermined area, such as cultivated field with water from a pressurized water supply, comprising in combination: a movable sprinkler carrier with a sprinkler head mounted thereon; a long, flexible water supply hose connected on one end thereof to the sprinkler head and capable of advancing the sprinkler carrier in the direction of the hose, when the latter is being pulled; a hose drum to which the other end of the water supply hose is permanently attached and which is capable of winding up substantially the entire length of the flexible supply hose in the form of a hose coil, the drum including a horizontal central shaft and two journals for the support of the shaft; a drum carriage in the form of a frame supporting the drum shaft by its two journals; a stationary drum carriage support, the support including a drum carriage guide permitting movement of the drum carriage in the sense of an axial displacement of the drum; means for continuously driving the drum so as to slowly wind up the water supply hose, thereby steadily advancing the sprinkler carrier in the direction in which the hose is being pulled; the drum driving means being mounted on the drum carriage and including a drive motor, a speed-reducing transmission between the drive motor and the drum shaft, and means for disconnecting the drum shaft from the transmission; means for simultaneously displacing the drum carriage and the drum in an axial direction at a rate which corresponds to the rate of axial increase or decrease of the hose coil on the drum as the hose is wound onto the drum or unwound from it, respectively, so that the axial point at which the straight portion of the hose extends from the drum remains the same with respect to the ground on which the device is stationed; and means for connecting the water supply to the attached end of the water supply hose in the hose drum, to allow pressurized water to flow through the rotating hose coil on the drum and through the straight portion of the water supply hose into the sprinkler head, as the latter is advanced toward the hose drum; said connecting means including a central duct inside the drum shaft, a connection between this duct and the attached end of the water supply hose, a rotary pipe coupling at one end of the drum shaft, and a water supply line linking the device to the pressurized water supply, the rotary pipe coupling including a non-rotating outer coupling portion to which one end of the water supply line is connected.
 3. A sprinkling device as defined in claim 2, wherein: the speed-reducing transmission includes a toothed wheel on the drum shaft, and the disconnecting means include a water-pressure-operated mechanical coupling between the toothed wheel and the drum shaft.
 4. A sprinkling device as defined in claim 3, wherein: the mechanical coupling between the toothed wheel and the drum shaft includes a hydraulic cylinder mounted on the drum shaft in parallel alignment thereto, and a spring-loaded piston with a piston rod extending from the cylinder toward the toothed wheel, the toothed wheel having a row of holes which can be engaged by the fully extended piston rod, when the piston is moved against its spring under the influence of the water pressure coming from the water supply, the spring causing the piston rod to release the toothed gear as soon as the water supply is shut off.
 5. A sprinkling device as defined in claim 2, wherein: the drum carriage guide on the carriage support includes two horizontally spaced, parallel guide profiles, and the drum carriage includes a plurality of oppositely arranged guide rollers engaging the two guide profiles.
 6. A sprinkling device as defined in claim 5, wherein: the drum displacing means include linear drive means on the drum carriage which engage the carriage support, and a fixed-ratio drive transmission between the drum shaft and the linear drive means.
 7. A sprinkling device as defined in claim 6, wherein: each of the two guide profiles includes a row of vertically oriented regularly spaced holes, and the linear drive means of the drum carriage include a transverse shaft journalled on the drum carriage and a sprocket on each shaft end engaging one of the two rows of guide profile holes in the manner of a rack-and-pinion drive; the fixed-ratio drive transmission including an intermediate shaft in parallel alignment with the drum shaft, a chain drive linking these two shafts, and a bevel gear connecting the intermediate shaft with the transverse shaft of the linear drive means.
 8. A sprinkling device as defined in claim 2, wherein: the hose drum has a cylindrical winding periphery and such an axial length that is can accommodate the entire coilable length of the water supply hose in a single-layer coil.
 9. A sprinkling device as claimed in claim 8, wherein: the stationary drum carriage support is a vehicle frame with two axles and four wheels thereon, representing a rectangular ground support area, the drum carriage and the drum carriage displacement means being so arranged that the empty hose drum at least partially overhangs the rear axle, while the drum driving means and drum displacement means, as well as the point at which the hose extends from the drum, remain located above the ground support area, whereas the full hose drum occupies a forward position in which its weight is distributed approximately evenly between the two vehicle frame axles.
 10. A sprinkling device as defined in claim 2, wherein: the hose drum has a cylindrical winding periphery and such an axial length that it can accommodate the coilable length of the water supply hose in two superposed layers of hose coil; and wherein the drum displacing means include means for reversing the direction of axial drum displacement, when the hose being wound onto the drum or unwound from the drum is beginning to create the outer coil layer or has fully removed the outer coil layer, respectively.
 11. A sprinkling device as defined in claim 2, wherein: the water supply line includes means for shutting off the water supply; and the device further includes means for closing these shut-off means and for stopping the drum motion in response to the completion of the hose-winding operation when the sprinkler carrier has reached its nearest position to the hose drum.
 12. A sprinkling device as defined in claim 2, wherein: the sprinkler head is a swivelling sector sprinkler covering a semicircular area extending away from the hose drum.
 13. A sprinkling device as defined in claim 2, wherein: the sprinkler head is a fixedly mounted sprinkler jet covering an approximately rectangular area extending to either side of the sprinkler carrier and away from the hose drum. 